A conventional method of measuring 3D objects is called stereo-vision that obtains paired stereo images taken of the same objects. When the imagery geometry model (IGM) of each image is given, the 3D coordinate information of the objects can be determined. A photogrammetric method surveys the objects by selecting conjugate points, and thereby measure any dimension using the IGMs based on these points. The 3D models and maps are then generated by using the stereo-vision approaches.
The acquisition of stereo images especially from airborne or satellite sensors is more expensive and needs a longer delivery time compared with acquiring single images. Also the majority of the archived images in the databases maintained by imagery vendors are single images. Therefore, the use of single images has advantages for applications such as emergency mapping, defense, intelligence, telecommunication and engineering etc.
There is no known system that has been developed to perform 3D measurement, modeling and mapping from the single images. The present invention has resulted in an operational method, computer program and system that can effectively obtain 3D measurements and create 3D object models and maps. The system is comprised of unique utilities and novel algorithms that are designed to make use of object projection, shadow, object geometry, and the IGM.
The IGM describes the geometric relationship between the object space and the image space, or vice visa. The two broadly used IGMs include the physical sensor model and the generalized sensor model. The rational function model (RFM) is a kind of generalized sensor model.
The following relevant prior art has been identified:
Jiang, W., Tao, C. V., Hu, Y., Xu, Z., 2003. 3-D measurement from single and stereo high-resolution satellite imagery based on the RFM, ASPRS Annual Conference, 5-9 May, Anchorage, Ak., 7 p. (This reference describes several experimental results obtained using RFM based methods from the satellite imagery)OpenGIS Consortium, 1999. The OpenGIS Abstract Specification—Topic 7. The Earth Imagery Case. (This reference provides an overview of IGMs used in the mapping, remote sensing and geospatial industry).Tao, C. V., Hu, Y., 2001. A comprehensive study of the rational function model for photogrammetric processing, Photogrammetric Engineering & Remote Sensing, 67(12): 1347-1357. (This reference provides a detailed mathematical formulation of the RFM sensor model and its experimental study on its accuracy).